This invention relates to off-board communication path structures for high frequency signal transmissions. More particularly, this invention relates to an interconnection plate between pc boards in which a high frequency transmission line structure is formed through a cross-section of the plate.
Communication paths for high frequency signals in the gigahertz range are often designed to minimize signal reflection at path media transitions. Signal reflection is undesirable as the signal is attenuated resulting in power loss. Accordingly, it is well known to match impedances among different media forming a high frequency signal path. In particular, impedance-matched transmission line structures are formed for on-board and off-board communications. Of interest here are path structures for off-board communication.
Conventional off-board communication path structures achieving transmission line effects for high frequency signals include semi-rigid cable assemblies. A semi-rigid cable assembly includes an outer semi-rigid metal tube concentrically surrounding an insulator concentrically surrounding an a central coaxial conductor. Typically, the cable assembly is terminated with a pair of mating connectors, one of which is attached to the semi-rigid cable and the other soldered to the pc board.
Such cable assemblies are bulky, awkward structures. Packaging of systems employing these assemblies require excess space for routing each cable. To reduce the associated packaging, fabrication and assembly costs, a less spacious, more compatibly-shaped structure is desired. A high frequency signal path structure is needed which achieves transmission line effects at a lower cost.